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MyungJoo Ham202f4f52010-08-20 14:43:56 +09001/*
2 * max8952.c - Voltage and current regulation for the Maxim 8952
3 *
4 * Copyright (C) 2010 Samsung Electronics
5 * MyungJoo Ham <myungjoo.ham@samsung.com>
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
11 *
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
20 */
21
22#include <linux/module.h>
23#include <linux/init.h>
24#include <linux/i2c.h>
25#include <linux/err.h>
26#include <linux/platform_device.h>
27#include <linux/regulator/driver.h>
28#include <linux/regulator/max8952.h>
MyungJoo Ham202f4f52010-08-20 14:43:56 +090029#include <linux/gpio.h>
30#include <linux/io.h>
31#include <linux/slab.h>
32
33/* Registers */
34enum {
35 MAX8952_REG_MODE0,
36 MAX8952_REG_MODE1,
37 MAX8952_REG_MODE2,
38 MAX8952_REG_MODE3,
39 MAX8952_REG_CONTROL,
40 MAX8952_REG_SYNC,
41 MAX8952_REG_RAMP,
42 MAX8952_REG_CHIP_ID1,
43 MAX8952_REG_CHIP_ID2,
44};
45
46struct max8952_data {
47 struct i2c_client *client;
48 struct device *dev;
MyungJoo Ham202f4f52010-08-20 14:43:56 +090049 struct max8952_platform_data *pdata;
50 struct regulator_dev *rdev;
51
52 bool vid0;
53 bool vid1;
MyungJoo Ham202f4f52010-08-20 14:43:56 +090054};
55
56static int max8952_read_reg(struct max8952_data *max8952, u8 reg)
57{
58 int ret = i2c_smbus_read_byte_data(max8952->client, reg);
59 if (ret > 0)
60 ret &= 0xff;
61
62 return ret;
63}
64
65static int max8952_write_reg(struct max8952_data *max8952,
66 u8 reg, u8 value)
67{
68 return i2c_smbus_write_byte_data(max8952->client, reg, value);
69}
70
MyungJoo Ham202f4f52010-08-20 14:43:56 +090071static int max8952_list_voltage(struct regulator_dev *rdev,
72 unsigned int selector)
73{
74 struct max8952_data *max8952 = rdev_get_drvdata(rdev);
75
76 if (rdev_get_id(rdev) != 0)
77 return -EINVAL;
78
Axel Linb9b49af2012-04-20 18:36:14 +080079 return (max8952->pdata->dvs_mode[selector] * 10 + 770) * 1000;
MyungJoo Ham202f4f52010-08-20 14:43:56 +090080}
81
Axel Linb9b49af2012-04-20 18:36:14 +080082static int max8952_get_voltage_sel(struct regulator_dev *rdev)
MyungJoo Ham202f4f52010-08-20 14:43:56 +090083{
84 struct max8952_data *max8952 = rdev_get_drvdata(rdev);
85 u8 vid = 0;
86
87 if (max8952->vid0)
88 vid += 1;
89 if (max8952->vid1)
90 vid += 2;
91
Axel Linb9b49af2012-04-20 18:36:14 +080092 return vid;
MyungJoo Ham202f4f52010-08-20 14:43:56 +090093}
94
Axel Lin6ea67d02012-03-26 09:20:58 +080095static int max8952_set_voltage_sel(struct regulator_dev *rdev,
96 unsigned selector)
MyungJoo Ham202f4f52010-08-20 14:43:56 +090097{
98 struct max8952_data *max8952 = rdev_get_drvdata(rdev);
MyungJoo Ham202f4f52010-08-20 14:43:56 +090099
100 if (!gpio_is_valid(max8952->pdata->gpio_vid0) ||
Jonghwan Choie2cf3132011-06-15 17:54:12 +0900101 !gpio_is_valid(max8952->pdata->gpio_vid1)) {
MyungJoo Ham202f4f52010-08-20 14:43:56 +0900102 /* DVS not supported */
103 return -EPERM;
104 }
105
Axel Lin6ea67d02012-03-26 09:20:58 +0800106 max8952->vid0 = selector & 0x1;
107 max8952->vid1 = (selector >> 1) & 0x1;
108 gpio_set_value(max8952->pdata->gpio_vid0, max8952->vid0);
109 gpio_set_value(max8952->pdata->gpio_vid1, max8952->vid1);
MyungJoo Ham202f4f52010-08-20 14:43:56 +0900110
111 return 0;
112}
113
114static struct regulator_ops max8952_ops = {
115 .list_voltage = max8952_list_voltage,
Axel Linb9b49af2012-04-20 18:36:14 +0800116 .get_voltage_sel = max8952_get_voltage_sel,
Axel Lin6ea67d02012-03-26 09:20:58 +0800117 .set_voltage_sel = max8952_set_voltage_sel,
MyungJoo Ham202f4f52010-08-20 14:43:56 +0900118};
119
Axel Linbd6ff0d2012-04-06 08:29:49 +0800120static const struct regulator_desc regulator = {
MyungJoo Ham202f4f52010-08-20 14:43:56 +0900121 .name = "MAX8952_VOUT",
122 .id = 0,
123 .n_voltages = MAX8952_NUM_DVS_MODE,
124 .ops = &max8952_ops,
125 .type = REGULATOR_VOLTAGE,
126 .owner = THIS_MODULE,
127};
128
129static int __devinit max8952_pmic_probe(struct i2c_client *client,
130 const struct i2c_device_id *i2c_id)
131{
132 struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
133 struct max8952_platform_data *pdata = client->dev.platform_data;
Mark Brownc1727082012-04-04 00:50:22 +0100134 struct regulator_config config = { };
MyungJoo Ham202f4f52010-08-20 14:43:56 +0900135 struct max8952_data *max8952;
136
137 int ret = 0, err = 0;
138
139 if (!pdata) {
140 dev_err(&client->dev, "Require the platform data\n");
141 return -EINVAL;
142 }
143
144 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE))
145 return -EIO;
146
Axel Lin372de4a2012-05-16 12:50:47 +0800147 max8952 = devm_kzalloc(&client->dev, sizeof(struct max8952_data),
148 GFP_KERNEL);
MyungJoo Ham202f4f52010-08-20 14:43:56 +0900149 if (!max8952)
150 return -ENOMEM;
151
152 max8952->client = client;
153 max8952->dev = &client->dev;
154 max8952->pdata = pdata;
MyungJoo Ham202f4f52010-08-20 14:43:56 +0900155
Mark Brownc1727082012-04-04 00:50:22 +0100156 config.dev = max8952->dev;
157 config.init_data = &pdata->reg_data;
158 config.driver_data = max8952;
159
Axel Linb669e0a2012-07-10 06:10:12 +0800160 config.ena_gpio = pdata->gpio_en;
161 if (pdata->reg_data.constraints.boot_on)
162 config.ena_gpio_flags |= GPIOF_OUT_INIT_HIGH;
163
Mark Brownc1727082012-04-04 00:50:22 +0100164 max8952->rdev = regulator_register(&regulator, &config);
MyungJoo Ham202f4f52010-08-20 14:43:56 +0900165
Axel Linda057382010-10-25 10:11:07 +0800166 if (IS_ERR(max8952->rdev)) {
167 ret = PTR_ERR(max8952->rdev);
MyungJoo Ham202f4f52010-08-20 14:43:56 +0900168 dev_err(max8952->dev, "regulator init failed (%d)\n", ret);
Axel Lin372de4a2012-05-16 12:50:47 +0800169 return ret;
Axel Linda057382010-10-25 10:11:07 +0800170 }
MyungJoo Ham202f4f52010-08-20 14:43:56 +0900171
Axel Linc8237f02012-03-15 08:47:48 +0800172 max8952->vid0 = pdata->default_mode & 0x1;
173 max8952->vid1 = (pdata->default_mode >> 1) & 0x1;
MyungJoo Ham202f4f52010-08-20 14:43:56 +0900174
MyungJoo Ham202f4f52010-08-20 14:43:56 +0900175 if (gpio_is_valid(pdata->gpio_vid0) &&
176 gpio_is_valid(pdata->gpio_vid1)) {
177 if (!gpio_request(pdata->gpio_vid0, "MAX8952 VID0"))
178 gpio_direction_output(pdata->gpio_vid0,
Axel Linc8237f02012-03-15 08:47:48 +0800179 (pdata->default_mode) & 0x1);
MyungJoo Ham202f4f52010-08-20 14:43:56 +0900180 else
181 err = 1;
182
183 if (!gpio_request(pdata->gpio_vid1, "MAX8952 VID1"))
184 gpio_direction_output(pdata->gpio_vid1,
Axel Linc8237f02012-03-15 08:47:48 +0800185 (pdata->default_mode >> 1) & 0x1);
MyungJoo Ham202f4f52010-08-20 14:43:56 +0900186 else {
187 if (!err)
188 gpio_free(pdata->gpio_vid0);
189 err = 2;
190 }
191
192 } else
193 err = 3;
194
195 if (err) {
196 dev_warn(max8952->dev, "VID0/1 gpio invalid: "
Lucas De Marchi25985ed2011-03-30 22:57:33 -0300197 "DVS not available.\n");
MyungJoo Ham202f4f52010-08-20 14:43:56 +0900198 max8952->vid0 = 0;
199 max8952->vid1 = 0;
200 /* Mark invalid */
201 pdata->gpio_vid0 = -1;
202 pdata->gpio_vid1 = -1;
203
204 /* Disable Pulldown of EN only */
205 max8952_write_reg(max8952, MAX8952_REG_CONTROL, 0x60);
206
207 dev_err(max8952->dev, "DVS modes disabled because VID0 and VID1"
208 " do not have proper controls.\n");
209 } else {
210 /*
211 * Disable Pulldown on EN, VID0, VID1 to reduce
212 * leakage current of MAX8952 assuming that MAX8952
213 * is turned on (EN==1). Note that without having VID0/1
214 * properly connected, turning pulldown off can be
215 * problematic. Thus, turn this off only when they are
216 * controllable by GPIO.
217 */
218 max8952_write_reg(max8952, MAX8952_REG_CONTROL, 0x0);
219 }
220
221 max8952_write_reg(max8952, MAX8952_REG_MODE0,
222 (max8952_read_reg(max8952,
223 MAX8952_REG_MODE0) & 0xC0) |
224 (pdata->dvs_mode[0] & 0x3F));
225 max8952_write_reg(max8952, MAX8952_REG_MODE1,
226 (max8952_read_reg(max8952,
227 MAX8952_REG_MODE1) & 0xC0) |
228 (pdata->dvs_mode[1] & 0x3F));
229 max8952_write_reg(max8952, MAX8952_REG_MODE2,
230 (max8952_read_reg(max8952,
231 MAX8952_REG_MODE2) & 0xC0) |
232 (pdata->dvs_mode[2] & 0x3F));
233 max8952_write_reg(max8952, MAX8952_REG_MODE3,
234 (max8952_read_reg(max8952,
235 MAX8952_REG_MODE3) & 0xC0) |
236 (pdata->dvs_mode[3] & 0x3F));
237
238 max8952_write_reg(max8952, MAX8952_REG_SYNC,
239 (max8952_read_reg(max8952, MAX8952_REG_SYNC) & 0x3F) |
240 ((pdata->sync_freq & 0x3) << 6));
241 max8952_write_reg(max8952, MAX8952_REG_RAMP,
242 (max8952_read_reg(max8952, MAX8952_REG_RAMP) & 0x1F) |
243 ((pdata->ramp_speed & 0x7) << 5));
244
245 i2c_set_clientdata(client, max8952);
246
Axel Linda057382010-10-25 10:11:07 +0800247 return 0;
MyungJoo Ham202f4f52010-08-20 14:43:56 +0900248}
249
250static int __devexit max8952_pmic_remove(struct i2c_client *client)
251{
252 struct max8952_data *max8952 = i2c_get_clientdata(client);
253 struct max8952_platform_data *pdata = max8952->pdata;
254 struct regulator_dev *rdev = max8952->rdev;
255
256 regulator_unregister(rdev);
257
258 gpio_free(pdata->gpio_vid0);
259 gpio_free(pdata->gpio_vid1);
MyungJoo Ham202f4f52010-08-20 14:43:56 +0900260 return 0;
261}
262
263static const struct i2c_device_id max8952_ids[] = {
264 { "max8952", 0 },
265 { },
266};
267MODULE_DEVICE_TABLE(i2c, max8952_ids);
268
269static struct i2c_driver max8952_pmic_driver = {
270 .probe = max8952_pmic_probe,
271 .remove = __devexit_p(max8952_pmic_remove),
272 .driver = {
273 .name = "max8952",
274 },
275 .id_table = max8952_ids,
276};
277
278static int __init max8952_pmic_init(void)
279{
280 return i2c_add_driver(&max8952_pmic_driver);
281}
282subsys_initcall(max8952_pmic_init);
283
284static void __exit max8952_pmic_exit(void)
285{
286 i2c_del_driver(&max8952_pmic_driver);
287}
288module_exit(max8952_pmic_exit);
289
290MODULE_DESCRIPTION("MAXIM 8952 voltage regulator driver");
291MODULE_AUTHOR("MyungJoo Ham <myungjoo.ham@samsung.com>");
292MODULE_LICENSE("GPL");